has an option for "ODBC Data" as a source (FileMaker looking at the SQL data).

Specify the data source name and location, the user ID and password (if any), and the SQL query to be executed. You can enter a query directly or specify a calculation to generate the query. For more information, see Automating ODBC import using the Import Records script step.

The first time you import, a table can also be created with the same name or another alias to the external SQL. The column/field names will be whatever is in the SQL table. Step through the Import dialog(s) and post screenshots if you get stuck somewhere.

Yes, you must import for each table. Yes, if you re-import you may need to decide what's new or changed or deleted. This is why many will use ESS (external SQL sources) instead of "Import". If you have the approved databases and ODBC drivers, you can see a "live view" of the SQL" data from inside FileMaker Pro. No SQL queries required.

Permissions, of course, are also a factor when communicating with External Sources (whether by ESS or Import).